Chapter 12.6. Surface Area and Volume of Spheres. Concept. Surface Area of a Sphere. Example 1. Find the surface area of the sphere. Round to the nearest tenth. S = 4 r 2 Surface area of a sphere = 4 (4.5) 2 Replace r with 4.5. ≈ 254.5 Simplify. Answer: 254.5 in 2.
Surface Area and Volume of Spheres
Find the surface area of the sphere. Round to the nearest tenth.
A. 462.7 in2
B. 473.1 in2
C. 482.6 in2
D. 490.9 in2
A. Find the surface area of the hemisphere.
A. 110.8 m2
B. 166.3 m2
C. 169.5 m2
D. 172.8 m2
B. Find the surface area of a sphere if the circumference of the great circle is 8 feet.
A. 100.5 ft2
B. 201.1 ft2
C. 402.2 ft2
D. 804.3 ft2
C. Find the surface area of the sphere if the area of the great circle is approximately 160 square meters.
A. 320 ft2
B. 440 ft2
C. 640 ft2
D. 720 ft2
Use a calculator.
Volumes of Spheres and HemispheresExample 3B
B. Find the volume of the hemisphere with a diameter of 6 feet. Round to the nearest tenth.
The volume of a hemisphere is one-half the volume of the sphere.
Volume of a hemisphere
Answer: The volume of the hemisphere is approximately 56.5 cubic feet.
A. Find the volume of the sphere to the nearest tenth.
A. 268.1 cm3
B. 1608.5 cm3
C. 2144.7 cm3
D. 6434 cm3
B. Find the volume of the hemisphere to the nearest tenth.
A. 3351.0 m3
B. 6702.1 m3
C. 268,082.6 m3
D. 134,041.3 m3
ARCHEOLOGYThe stone spheres of Costa Rica were made by forming granodiorite boulders into spheres. One of the stone spheres has a volume of about 36,000 cubic inches. What is the diameter of the stone sphere?
Understand You know that the volume of the stone is 36,000 cubic inches.
Plan First use the volume formula to find the radius. Then find the diameter.
RECESS The jungle gym outside of Jada’s school is a perfect hemisphere. It has a volume of 4,000 cubic feet. What is the diameter of the jungle gym?
A. 10.7 feet
B. 12.6 feet
C. 14.4 feet
D. 36.3 feet